1. Field of the Invention
The present invention relates to a total system rotation type scroll compressor having a driving scroll and driven scroll.
2. Discussion of Background
The principle of the scroll compressor has been known. The scroll compressor is a kind of a positive displacement type compressor in which a pair of scrolls are combined with each other to effect compression of a fluid.
In the ordinary scroll compressor, one of the scrolls is made stationary and the other is subject to an orbital movement with respect to the stationary scroll to effect the compression.
The principle of the total system rotation type scroll compressor in which both scrolls are respectively rotated around their own axial center, is also well known.
FIG. 6 shows the principle of the total system rotation type scroll compressor. A driving scroll 1 is caused to rotate around its own axial center O.sub.1 by a driving source such as a motor, an engine, a turbine and so on. A driven scroll 2 is also caused to rotate around its axial center O.sub.2 in synchronism with the rotation of the driving scroll 1. A compression chamber 3, which is formed by combining the driving and driven scrolls 1, 2, moves toward the rotation centers as the both scrolls rotate while the volume of the chamber 3 is gradually reduced. The pressure of a gas confined in the compression chamber 3 increases and a highly pressurized gas is discharged through a dischage port 2c.
FIG. 6a shows a state of the combined driving and driven scrolls 1, 2 at its moving phase of 0.degree., in which the gas is sucked in the compression chamber 3. As the scrolls rotate, they assume the moving phase of 90.degree., 180.degree., 270.degree. and 360.degree. C. (0.degree.) succesively, whereby the compression chamber 3 gradually shifts toward their revolution centers with the result of reduction in the volume of the gas. The two scrolls 1, 2 provide sealing portions by mutual contact of the side surfaces of the wrap plates 1a, 2a of the scrolls 1, 2. As shown in FIG. 6, the sealing portions s are in alignment with each other in the radial direction of the driving and driven scrolls 1, 2; namely, they always take a constant positional relation in a static state of the scrolls.
U.S. Pat. No. 3,884,599 schematically shows the conventional total system rotation type scroll compressor. In the construction disclosed in the U.S. patent, an Oldham coupling is used to maintain a given phase between a driving scroll and a driven scroll and to transmit a torque.
The conventional scroll compressor has disadvantages as follows. It is provided with a sliding part in which structural elements undergo a reciprocating movement on the sliding surface of the sliding part. Accordingly, mass in the construction is large and therefore, it is not suitable to perform a high speed revolution.
Further, since the Oldham's coupling is arranged around the both scrolls, the size of the scroll compressor is large.